package com.baomidou.kisso.common.bcprov.util.encoders;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import com.baomidou.kisso.common.bcprov.util.Strings;

public class Hex {

	private static final Encoder encoder = new HexEncoder();


	public static String toHexString( byte[] data ) {
		return toHexString(data, 0, data.length);
	}


	public static String toHexString( byte[] data, int off, int length ) {
		byte[] encoded = encode(data, off, length);
		return Strings.fromByteArray(encoded);
	}


	/**
	 * encode the input data producing a Hex encoded byte array.
	 *
	 * @return a byte array containing the Hex encoded data.
	 */
	public static byte[] encode( byte[] data ) {
		return encode(data, 0, data.length);
	}


	/**
	 * encode the input data producing a Hex encoded byte array.
	 *
	 * @return a byte array containing the Hex encoded data.
	 */
	public static byte[] encode( byte[] data, int off, int length ) {
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();

		try {
			encoder.encode(data, off, length, bOut);
		} catch ( Exception e ) {
			throw new EncoderException("exception encoding Hex string: " + e.getMessage(), e);
		}

		return bOut.toByteArray();
	}


	/**
	 * Hex encode the byte data writing it to the given output stream.
	 *
	 * @return the number of bytes produced.
	 */
	public static int encode( byte[] data, OutputStream out ) throws IOException {
		return encoder.encode(data, 0, data.length, out);
	}


	/**
	 * Hex encode the byte data writing it to the given output stream.
	 *
	 * @return the number of bytes produced.
	 */
	public static int encode( byte[] data, int off, int length, OutputStream out ) throws IOException {
		return encoder.encode(data, off, length, out);
	}


	/**
	 * decode the Hex encoded input data. It is assumed the input data is valid.
	 *
	 * @return a byte array representing the decoded data.
	 */
	public static byte[] decode( byte[] data ) {
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();

		try {
			encoder.decode(data, 0, data.length, bOut);
		} catch ( Exception e ) {
			throw new DecoderException("exception decoding Hex data: " + e.getMessage(), e);
		}

		return bOut.toByteArray();
	}


	/**
	 * decode the Hex encoded String data - whitespace will be ignored.
	 *
	 * @return a byte array representing the decoded data.
	 */
	public static byte[] decode( String data ) {
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();

		try {
			encoder.decode(data, bOut);
		} catch ( Exception e ) {
			throw new DecoderException("exception decoding Hex string: " + e.getMessage(), e);
		}

		return bOut.toByteArray();
	}


	/**
	 * decode the Hex encoded String data writing it to the given output stream,
	 * whitespace characters will be ignored.
	 *
	 * @return the number of bytes produced.
	 */
	public static int decode( String data, OutputStream out ) throws IOException {
		return encoder.decode(data, out);
	}
}
